Serpent sting: DoT that does nature damage. This is one of the first skills you use when you open on someone. Chimera refreshes the duration. The glyph increases duration by 6 seconds, which also increases chimera shot damage.
Chimera shot: deals 125% weapon damage and does something according to the sting you have on the target. Serpent sting: instantly deals 40% of the total damage of the serpent sting and refreshes it. Scorpid sting: disarms the target for 10 seconds and refreshes it. Viper sting: instantly restores mana equal to 60% of the total amount drained by your sting and refreshes it. This is your main shot as an MM hunter, does most damage of all abilities.
Silencing shot: silences the target for 3 seconds and deals 50% weapon damage. If you are versing a warrior in a duel for example, you can use silencing shot. Silencing shot triggers no global cooldown so you can silence shot + chimera shot at the exact same time for extra burst. You can also silence a healer and chimera shot another person at the exact same time.
Aimed shot: deals damage (bit less than chimera) and reduces healing done to the target by 50% for 10 seconds. With the glyph you will be able to always have aimed shot up (healing reduction).
Arcane shot: deals arcane damage. Don't expect alot of damage from this.
Detterence: you will deflect/parry everything, you won't get any damage. Be aware though, DoT's go through deterrence and so do a certain amount of abilities like backstab, shred, etc.. A great thing to have though. Use deterrence to avoid insane burst or when you need to be safe when on low hp.
Readiness: finishes the cooldown of all your hunter abilities. You can chimera, silence, deterrence twice with this. Use it carefully, be sure to use it as effective as possible, don't use readiness when you still have silence, chimera shot & readiness at the same time. Try to make it reset as much cooldowns as possible. Profit.
Concussive shot: dazes the target for 4 sec. Doesn't do any damage, only use it when you really have to kite a warrior and you don't got anything else to kite him. There are better ways than concussive shot to kite someone (snake trap, frost trap, wing clip, chimera shot's daze, pet root/stun, scatter shot, etc.)
Disengage: makes you leap backwards. Awesome skill for a hunter, it's a key ability. You can easily run away from a fight in a battleground or kite someone with it.
Kill shot: serious business. Only useable if the target has less than 20% hp, does serious damage. Nothing more to say.
Volley: only use it to get stealthed people out of stealth. The damage isn't any good, and even in big battlegrounds like AV it isn't worth it. This eats your mana, don't spam it too much to get a rogue out of stealth, try and use aspect of the viper while volleying to prevent getting on low mana before the fight even starts.
Scatter shot: great opener in duels and the best thing ever to trap someone. Use scatter shot and then trap for an effective trap.
Frost trap: AoE slowing trap. It creates a freezy area and everyone who runs into it will get slowed by 50%. With entrapment (talent) they will get entrapped for 4 seconds, preventing them from moving. Frost trap and freezing trap share cooldowns, so if you use this slowing trap, you won't be able to trap (CC) someone else.
Hunter's mark: your basic opener. Grants everyone (which means only hunters, really) 500 ranged attack power. Also, the hunter can always see marked targets, even if they are in stealth (rogue for example). Rogues can cloak of shadows this though, and will always do that, so don't feel overconfident when you mark a rogue.
Freezing trap: CC's someone for 10 seconds. It lands in front of your feet, so don't use it to trap healers in arena.
Rapid fire: Increases ranged attack speed by 40% for 15 sec. Says enough, no? PEW PEW! You can use it at start of your rotation for superior burst or use it to steady shot faster.
Master's call: removes all movement impairing effects from your pet and your target and makes it immune for 4 seconds. If an enemy target is targetted or you have no one targetted, you will masters call yourself. You can use it on other people (your arena partner) too, but 99% of the times you will use it on yourself.
Snake trap: summons snakes who do a bit of damage and slow the target and increase their casting time of spells. It's annoying for everyone. With entrapment this will entrap them for 4 seconds. Good for kiting. Be aware of using it in arena though, this does damage and therefore gets healers out of CC.
Wing clip: slows the target for 10 seconds, you have to be in melee range. Don't run up to a warrior to wing clip him, just use it when he charges you.
Feign death: makes you pretend to be dead. No one will believe it, right? True. But it interrupts people and makes them have to retarget you. If you feign death they lose the target on you. If someone is casting immolate, just use feign death and their immolate will be cancelled. Glyph reduces cooldown by 5.
Scorpid sting: reduces chance to hit with melee and ranged attacks by 3%, this sting is mostly used to either change another sting (someone is afflicted with serpent sting and you want to CC them, you use scorpid sting which does no damage so you can go and CC that person) or to chimera shot after it so it disarms them.
Steady shot: causes weapon damage + ammo + 799. It's the only shot that you have to actually stand still for and cast. Only use it when you have no other shot on cooldown and when you have the time to do so. 90% of the times you won't use steady shot because you don't have enough time to do so.
Aspect of the viper: regenerates mana on all attacks and regenerates 4% mana of your max mana every 3 seconds. Damage is reduced by 50%. It's good to use it when you're low on mana, but don't forget to switch back to aspect of the dragonhawk after it, or you will do 50% damage the whole time while you have full mana.
Aspect of the dragonhawk: your main aspect. Gives 300 attack power and 18% dodge. Use it at all times.
Aspect of the cheetah: increases movement speed by 30%. Only use it when you're not getting attacked, you will get dazed when you get hit by something.
Viper sting: drains mana from the target. Nothing much to say here.
Scare beast: scares beasts. Useable on feral druids, shamans in ghost wolf form and hunter pets.
Mend pet: HoT which heals your pet.
Tranquilizing shot: removes 1 enrage and 1 magic effect from the enemy. You can dispel Blessing of Protection (BoP) with this, fear ward, etc. Chances aren't high you will get it off if the target has a lot of buffs on him. Test your luck!
Trueshot aura: ALWAYS have it up. 10% attack power, who doesn't want that?
Freezing arrow: your main CC as a hunter, it freezes a target for 10 seconds, you can shoot this arrow. Always use it after scatter shot so you know the enemy will get trapped. If you scatter shot, the person will walk in a certain pattern, after a few times you will know where to drop your freezing arrow. ANY damage will break this effect, so be aware.